1. Field of the Invention
This invention is directed to systems and methods for dehumidifying a space within an interior of a building.
2. Related Art
Various conventional systems for dehumidifying a large interior space by connecting a dehumidifier to the interior space through duct work are known. In general, such systems are commonly referred to as whole-house dehumidifier systems, because such systems often are connected to the duct work of a forced-air heating, ventilation and air conditioning (HVAC) system that extends throughout a whole house or other type of building.
For example, U.S. Pat. No. 5,598,715 discloses a by-pass dehumidifier that is connected to and receives air to be dehumidified from an HVAC system and that returns the dehumidified air back to the HVAC system. The 715 patent is incorporated herein by reference in its entirety. In the system disclosed in the '715 patent, air is withdrawn from the HVAC system at a point downstream from the furnace/air conditioning unit, such that the conditioned air from the HVAC system passes to the dehumidifier unit. After the dehumidifier removes moisture from the air received from the HVAC system, the dehumidified air is returned to a point upstream of the furnace/air conditioning unit. The system disclosed in the '715 patent uses this flow because it allows the dehumidifier to use the fan or blower of the HVAC system to drive air through the dehumidifier, as well as through the duct work leading from the HVAC system to the dehumidifier and from the dehumidifier back to the HVAC system.
To determine whether to dehumidify the air coming from the HVAC system, the system disclosed in the '715 patent measures the relative humidity within the interior space that is supplied with conditioned air by the HVAC system. In particular, depending on the value of the relative humidity of the interior space, as measured by a humidistat, relative to a predetermined control value, the system disclosed in the '715 patent either opens or closes a damper. When the damper is opened, air can flow from the HVAC system into the ductwork leading to the dehumidifier. In contrast, when the damper is closed, the dehumidifier is disengaged from the conditioned air being supplied from the furnace/air conditioner unit of the HVAC system.
Therma-Stor Products of Madison, Wis. distributes a second conventional whole-house dehumidifier system that operates in parallel with a forced-air HVAC system. In particular, this Therma-Stor system uses one or both of a dedicated duct that draws air from the interior space into the dehumidifier and a dedicated duct that draws outside air into the dehumidifier. In this Therma-Stor system, the dehumidifier has its own fan or blower that is controlled by a control panel located in an interior space that is to be supplied with dehumidified air from the dehumidifier. The dehumidified air output by the dehumidifier passes through a dedicated duct between the dehumidifier unit and the ductwork of the HVAC system. In particular, in this Therma-Stor product, the dehumidifier returns the dehumidified air to a point in the HVAC system's ductwork that is downstream from the furnace/air conditioner unit of the HVAC system. Like the system disclosed in the '715 patent, this Therma-Stor system measures the relative humidity of the air in the interior space and turns on the dehumidifier when the relative humidity in the interior space is greater than a predetermined control value. The Therma-Stor dehumidifier continues to run until the relative humidity in the interior space drops below the predetermined control value.
A third conventional dehumidifier system, also distributed by Therma-Stor, withdraws air to be dehumidified from an interior space through a dedicated duct that leads to the dehumidifier. However, unlike the previously-discussed conventional dehumidification's systems, this second Therma-Stor product does not return the dehumidified air back to the ductwork of an HVAC system or through a second duct back into the interior space. Rather, this second Therma-Stor product merely outputs the dehumidified air locally to the dehumidifier in the room in which the dehumidifier unit is placed. Thus, this third conventional dehumidification system operates by having the dehumidified air diffuse back into the other interior spaces. Like the first two conventional systems, this third conventional system also operates by measuring the relative humidity using a humidistat and controlling the operation of the dehumidifier based on the measured relative humidity.
It should also be appreciated that common portable dehumidifiers operate substantially similarly to this third conventional dehumidifier system, except that portable dehumidifiers omit the duct work entirely. Thus, portable dehumidifiers both draw from and output to their immediate ambient environment.